Process for the collective fabrication of 3D electronic modules

A method of fabricating n electronic modules, n being an integer greater than 1, a module comprising a stack of K electronic wafers, a wafer i, i varying from 1 to K comprising on an insulating substrate at least one electronic component, the K wafers being electrically interlinked by conductors located on the lateral sides of the stack, wherein the fabrication is collective, comprising the steps of:

• a first step comprising, for each wafer i, in:
• A1) a step for fabricating a batch of n wafers i on one and the same flat thin sheet of thickness ep comprising silicon, covered on one face with a thin electrically insulating layer of thickness ei, forming the substrate, with, on this face, grooves of width L1 and of depth greater than ei and less than ep+ei, these grooves delimiting at least n geometrical patterns, each pattern being provided with at least one silicon electronic component connected to electrical connection terminals disposed on said face, the terminals being linked to electrical connection elements extending at least as far as a groove, a hole-opening area being provided at the intersection of the grooves and of the connection elements, the transverse dimension of this area being less than L1, the components being coated with an insulating resin which also fills the grooves,
• B1) a thinning step by surface grinding of the other face of the sheet so as to reveal the resin of the grooves,
• a second step comprising:
• A2) stacking and assembling the K batches obtained on completion of the first step, so as to superimpose the opening areas, substantially one on top of the other,
• B2) drilling holes in the resin perpendicularly to the faces of the sheets through the entire thickness of the stack plumb with the opening areas, the transverse dimension of the holes being less than L1, so that the silicon is insulated from the wall of the hole by the resin,
• C2) metallizing the wall of the holes,
• D2) cutting the stack along the grooves in order to obtain the n electronic modules.